Railway traffic controlling apparatus



Oct. 8, 1940. J. H. BROADBENT 2,217,508

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed July 6, 1939 2 Sheets-Sheet J.

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H S ATTORNEY c 8, 1940- J. H. BROADBENT RAILWAY TRAFFIC CQNTRQLL ING AFPARATUS Filed July 6, 1939 2 Sheets-$hee1 2 T m m B 7c 7:5: 53 1T 5L 1 m W 3 0 w W 2 g B [Pu 9 C a 2 9 5 7m 5 W m? N W B m 5 T R i w 0 3 T4 INVENTOR HIS TTORNEY Patented Oct. 8, 1940 UNITED STATES truss RAILWAY TRAFFIC CONTROLLHNG APPARATUS Application July 6, 1939, Serial Nd. 283,043

11 Claims.

My invention relates to railway traffic controlling apparatus, and has particular reference to the organization of such apparatus to provide approach control in railway traffic controlling energy is utilized to control either or both wayside signals and train carried cab signals.

Railway trafic controlling systems of the above class are particularly suitable for controlling is multiple indication wayside signals without employing line wires or auxiliary conductors other than the track rails, the control of each signal being established in accordance with the code rate at which trackway energy is applied to its associated track section. In accordance with the usual signaling practice, the selection of the particular code rate at which trackway energy is supplied to a section is determined by traffic conditions in advance of such section, hence so such coded energy is supplied to the section at its exit end and is received by a code responsive track relay positioned adjacent the signal or entrance end of the section.

In connection with a system of the above class, 25 it is often desirable to provide approach control or operation, that is, it is desirable to control a normally inactive control device to an active condition in response to trafiic conditions in the rear of such device. For example, normally dark 30 traffic controlling signals may be approach operated or lighted; signals and/or track switches may be locked against operation upon the approach of a train; and highway crossing signals positioned at a railway-highway intersection may he set into operation in advance of the time that a train reaches the intersection. Other classes of control devices will readily suggest themselves to those trained in the art as being desirably approach operate-d.

40 Accordingly, an object of my invention is the organization of railway trafiic controlling apparatus into normal and improved forms of railway signaling systems providing approach control or operation of control devices.

Another object is the provision of novel and improved means for efiecting approach control or operation of a control device in railway traffic controlling systems utilizing coded trackway energy.

50 An additional object is to effect the above named approach operation by novel and improved means requiring but a single auxiliary conductor for the control section located in the rear of the device to be controlled.

55 A further object is to provide means wherein a systems of the class wherein coded trackway track rail of an adjacent stretch of track is utilized as the named auxiliary conductor.

Another object is to provide means controlled by traffic in either of twoadjacent tracks for establishing approach control of a control device.

Other objects and advantages of my invention will appear as the description proceeds.

I shall describe three forms of apparatusembodying my invention, and shall then point out the novel features thereof in claims. m

In the accompanying drawings, Fig. 1 is a diagrammatic, view of one form of apparatus embodying my. invention as applied to a system providing approach operation or lighting of tramc controlling signals. Figs. 2 and 3 are modified forms of the apparatus shown in Fig. 1, each also embodying my invention. 7

Similar reference characters refer to similar parts in each of the three views;

Referring first to Fig. 1,.the reference characters D and E each designate a different one of two tracks of a stretch of multiple track railway, trafiic normally moving in both tracks in the single direction indicated by arrows in Fig. l, or from left to right as viewed in the drawing. The track rails I and la of;track D are divided by means of the usual insulated rail joints 5 into a plurality of successive adjoining track sections, of which only one section -lii is shown complete in the drawing. Similarly, the track rails Z and 2a of track E are divided also by insulated rail joints 3 into a plurality of successive adjoining track sections, only one section 6-l being shown complete in the drawing. Preferably the sections of each track D and E are coextensive. I

Each section of the tracks D and E is provided with a signal, designated by the reference character S with a suitably distinguishing suiiix, located adjacent the entrance end of the section for governing traffic operating thereover. Signals S are normally dark, and are at times controlled to an illuminated condition in a manner to be explained in detail hereinafter. The signals may take anyone of many suitable forms, but as herein shown are three-indication signals of the color light type and comprise a red lamp R,

a yellow lamp Y and a green lamp G, which lamps when illuminated indicate stop, approac and clear, respectively.

Each section also is provided with the usual coded track circuit apparatus, and which apparatus comprises means for supplying coded trackway energy to the rails of the section at its exit end, and a code responsive track relay connected across the rails of the section at its entrance 55 end. The track circuit apparatus of sections 4-5 and 6-2 of tracks D and E are substantially similar, so that the following detailed description of the track circuit apparatus of section 6-1 of track E will SllfiIlCB also to describe the track circuit apparatus of section 3-5 of track D.

Section 6-? is supplied with coded trackway energy in the usual manner by means including a track transformer TTl which has its secondary winding constantly connected across the track rails of section 5-? adjacent its exit end 7, and has its primary winding connected with a suitable source of alternating current (such as a generator not shown in the drawings) having its terminals designated by the reference characters BX and GK, and which alternating current is periodically interrupted or coded by means of a coding device CT. It is to be understood, of course, that the apparatus supplying trackway energy to section 5-! may, if so desired, be controlled by traihc conditions in advance of section 6-? through the medium of control apparatus of the well-known form (not shown in the drawings) and that such trackway energy may be coded at any one of a plurality of rates (usually at the rates of and 180 impulses per minute in the case of a three-indication signal) for selectively controlling the multiple indication signal associated with that section. Coding device CT normally is energized continuously from the source of alternating current.

The track circuit of section 6-! also includes a code responsive track relay, designated by the reference character TR with a distinguishing suffix, connected with the rails of the section adjacent its entrance end 6 through the medium of a relay transformer RTE and a rectifier 8 which rectifies the alternating trackway energy received from section 6-? into and supplies relay TR6 with impulses of unidirectional current. Associated with track relay TRS of section 6-! is the usual decoding apparatus 9 which functions in the customary manner to selectively control, in accordance with trafiic conditions in section 6-1, the code rate or frequency at which trackway energy is supplied to .the section next in the rear of section 6-7, that is, the section lying immediately to the left of section 6-! as viewed in the drawings.

The decoding apparatus 9 (the details of which are not shown in the drawings for the sake of simplicity) of section 6-? also functions to selectively control its associated signal S6 by set ting up a lighting circuit for one or another of the lamps R, Y and G of such signal. As was pointed out heretofore, signal S5 is normally dark, and is at times supplied with energizing current from a suitable source, such as a battery not shown in the drawings, having its two terminals designated. by the reference characters B and C. r

In order that the normally inactive signals may be rendered active upon the approach of a train to the signals, the coextensive sections of the two tracks D and E are provided with means including a normally energized approach lighting relay AR, which relay is controlled by trafiic conditions in each of the two coextensive sections for operating the signals located in advance of such sections to an active condition upon the approach of a train to such signals. Each approach lighting relay is effective when deenergized to connect the source of current to the energizing or lighting circuit set up by the decoding apparatus associated with the signal S located in advance of the section. For example, relay AR (which is controlled by traffic conditions in each of the coextensive sections 4-5 and 6-! in a manner to be pointed out presently) connects over its back contacts l2-l2h and l3-i3b the B terminal of the source of current with the lighting circuit set up for each signal S? and S5 by its associated decoding apparatus 9, thereby controlling the signals located in advance of sections 4-5 and 6-7 to their illuminated or active condition.

Control of relay AR is established by means of a circuit supplied with energy from 'a suitable source, such as battery I l, and controlled by the track relays of each of the two sections ii-5 and 6-1. This circuit of relay AR may be traced from one terminal of battery it through front contact Iii-l 5a. of code following track relay T'R i of section 4-5, front contact lG-lGa of a slow releasing track repeater relay 'IPR (which is controlled over an obvious circuit including front contact ll-I 1a of code following track relay TRG of section 6-7 and which is proportioned'to remain picked up whenever relay IRS is steadily energized or is following code), track rail 2 of section 6-1, the winding of relay AR and track rail Ia of section 4-5 to the other terminal of battery I).

Relay AR is provided with slow releasing characteristics (effected in part by means of a shortcircuiting resistor l8 connected across its terminals) whereby the relay is maintained picked up during the off or no-energy period of the impulses of energy supplied to its circuit when relay TPR is picked up and relay TR l is following code.

In operation, as long as sections 4-5 and 6-1 are unoccupied so that coded trackway energy is received from such sections by the associated track relays TR4 and TRli, relay AR will be picked up over its previously traced circuit, which is supplied with energy during the intervals that front contact l5-l5a of relay TRd is closed in response to the coded trackway energy received from section 4-5. Relay AR picked up opens at its back contacts l2-l2b and I3-l3b the energizing circuits for signals ST and S5, and as a result signlas S7 and S5 normally are in their darkened condition.

Whenever either section 3-5 or 6-! becomes occupied by a train so that the trackway energy is shunted away from its associated track relay, the release of that relay results in the opening of the circuit for relay AR and consequent lighting of both signals S5 and S? located in advance of the section. For example, in the event that section 6-! is occupied and relay TRS releases, relay TPR also is released and opens its front contact Iii-Ilia to open the previously traced circuit of relay AR. With relay TPR released, relay AR then is connected in a shunt circuit over back contact lB-iGb of relay TPR, thereby insuring the release of relay AR. Also, if section 4-5 is occupied, then the inactive condition of relay TR4 interrupts over its front contact I' l5a the supply of energy to the circuit of relay AR, and also connects relay AR in a shunt circuit over back contact l5-I5b of relay 'IR l and front contact IG-lfia of relay TPR, thereby insuring release of relay AR. Relay AR accordingly is governed by trafiic conditions in each of the two coextensive sections 5-5 and 6-7, the F control being established by virtue of the fact that trackway energy is shunted away from one or the other or both of the track relays whenever one or the other or both of the sections are occupied.

Whenever both sections 45 and 6-! again become unoccupied so that relays 'I'R4 and TRG again respond to the trackway energy supplied to the rails of the associated sections, the circuit of relay AR is reestablished and relay AR picks up to control signals S5 and S1 to their normally darkened conditions.

From the foregoing, it can be seen that approach control is established for a traffic controlling system utilizing coded trackway energy, without requiring any accessory or auxiliary line wires. It should be pointed out that relay AR is controlled by traffic in each section 4-5 and 61 over a circuit including a track rail of the section occupied, and a track rail of the other section, the latter rail functioning as an auxiliary conductor to the rail of the occupied section included in circuit with relay AR to thereby complete such circuit. Each track relay of the two tracks D and E, therefore, controls the approach control relay over a circuit including one track rail of its associated track and an auxiliary conductor comprising one track rail of the adjacent track. By utilizing a single track rail of two adjacent tracks to establish a circuit for the approach control relay, it is readily apparent that approach control is established without employing auxiliary line wires, thereby avoiding loss of auxiliary control such as might result due to pole line failures.

Referring now to Fig. 2, the apparatus of Fig. 1 is herein shown modified in such manner that approach control relay AR of Fig. 2 is controlled by virtue of a phantom circuit which includes the two track rails l and la of track D in parallel and also includes the two track rails 2 and 2a of track E in parallel. Specifically, the circuit for relay AR of Fig. 2 passes from one terminal of battery id of Fig. 2 through front contact l'5-i5a of relay 'IR l, front contact l6l6a of relay TPR, center tap of impedance bond 20 (which is connected across the two track rails 12 and 2a of track E of Fig. 2), the two track rails 2 and 2a of track E in parallel, impedance bond 2i to its center tap, the winding of relay AR of Fig. 2, center tap of impedance bond 22 (which is connected across the two track rails l and la of track D of Fig. 2), the two track rails l and id of track D in parallel, and impedance bond 23 to its center tap to the other terminal of battery !4.

It is believed that the operation of the apparatus of Fig. 2 will be readily apparent from an inspection of Fig. 2 together with the foregoing description of Fig. l, and further detailed explanation is deemed unnecessary, except to point out that both track rails of track D are connected in parallel, and that both track rails of track E also are connected in parallel in the circuit of the approach control relay AR of Fig. 2. It is readily apparent that, since the rails of track D (and of track E also) are connected in parallel, a train on track D or E will not control the circuit of relay AR by establishing a train shunt'on such circuit, but rather that such control of the circuit is established through the medium of track relay TBA and repeater relay TPR, as was explained in detail in connection with the apparatus of Fig. 1.

Referring now to Fig. 3, another modification of the apparatus of Fig. 1 is shown applied to a single track railway E over which traffic normally moves in the single direction indicated by an arrow in Fig. 3. In Fig. 3, a code following track repeater relay TPCR is employed to control approach control relay AR of Fig. 3 through the medium of a decoding transformer UT. The energizing circuit for code following relay TPCR of Fig. 3 passes from one terminal of battery l4 through front contact |1lla of relay TRB,

conductor 25, the winding of relay TPCR, center tap of impedance bond 2! (connected across the two track rails 2 and 2a of track E), the two track rails 2 and 2a of track E in parallel, and impedance bond 20 to'its center tap to the other terminal of battery l4.

A portion of primary winding 26 of decoding transformer DH is supplied with direct current over an obvious circuit including front contact ll-Zia of relay TPCR, and the remainder of primary winding 26 of transformer DT is supplied with direct current over an obvious circuit which includes back contact 21--2'Ib of relay TPCR. Secondary winding 28 of transformer DT is connected across the terminals of relay AR of Fig. 3 over anobvious circuit completed over front contact 29--29a of relay TPCR, and relay AR is provided with a short-circuiting path which includes a resistor l8 and back contact 29-491) of relay TPCR, this latter path functioning to impart slow releasing characteristics to relay AR, with the result that relay AR is maintained picked up whenever relay TPCR is operating on coded energy. Relay AR, as shown, controls; signal S! located in advance of section ,6l, to an illuminated condition whenever its back contact l2l2b is closed. Relay AR, however, normally is energized in response to the coded energy supplied to the decoding transformer DT by relay TPCR, which latter relay normally is supplied with coded energy through its previously traced circuit as a result of track relay TRB following the coded trackway energy supplied to section 6-! by code transmitter CT.

When, however, section i3"-'! is occupied by a train so that the coded trackway energy of the section is shunted away from relay TRfi, and as a result front contact ll-lla of relay TRB is held open, relay TPCR no longer is supplied with coded energy and consequently releases to open at its front contact 2929a the circuit connection of secondary winding 23 of transformer DT with, relay AR. Relay AR consequently releases, with the result that signal S 1 is controlled to its illuminated condition. Also, in the event that track relay TRE is continuously held picked up in response to steady static or non-coded energy from the rails of section 6'l, then front contact lllla of relay TRB is continually closed and relay TPCR is held continuously picked up. Pri mary winding 26 of decoding transformer DT accordingly is continuously supplied with direct current during this interval, and relay AR is connected across secondary winding 28 of decoding transformer DT. However, it is readily apparent that with transformer D-T supplied with direct current, no transformer action is effected by this current so that relay AR is caused to be released to control signal S! to its illuminated condition. It follows, therefore, that signal S1 is controlled to its illuminated condition at all times except when relay TPC'R is following code.

It should be pointed out that in Fig. 3, the track rails 2 and 2a; of section 6'! are employed in parallel as a portion of the circuit which controls approach control relay AR, and that but a single auxiliary or line wire other than the track rails of a section is required to control the approach control relay associated with that section.

It is to beunderstood, of course, that while traffic controlling signals only have been illustrated as being controlled by apparatus embodying my invention, other control devices or apparatus may be controlled if desired, the control being established through the medium of the approach control relay AR, as hereinbefore explained.

It should also be understood that although apparatus embodying my invention is herein illustrated and described in connection with a railway signaling system employing coded trackway energy, such apparatus is equally well adapted for use with signaling systems utilizing noncoded or steady trackway energy.

Although I have herein shown and described only three forms of railway traffic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a section of railway track, means for supplying periodically interrupted trackway energy to the rails at one end of the section, a track relay connected with the rails at the other end of said section and arranged to follow the periodic interruptions of said trackway energy, an auxiliary conductor, an approach relay, connected in circuit with said auxiliary conductor and at least one of the track rails of said section, and a source of current connected to said circuit over a front contact of said track relay.

2. In combination, a section of railway track having means for supplying trackway energy of one character to the rails at one end of said section, a track relay positioned at the other end of said section and responsive to said trackway energy, an auxiliary conductor, an approach relay positioned at said one end of said section and connected in circuit with said auxiliary conductor and at least one of the track rails of said section, and a source of energy having characteristics differing from said trackway energy connected over a front contact of said track relay to said circuit 3. In combination, a double track railway, an insulated track section for each of the two tracks of said railway, means for supplying 'trackway energy to each of said track sections, approach control relay means, and a circuit for said approach control relay means including at least one track rail of each of said track sections and controlled by the trackway energy of each of said track sections.

4. In combination, a multiple track railway, an insulated track section for each of a selected two tracks of said railway, a track circuit including a track relay for each of said track sections, an approach control relay, and means controlled by each of said track relays for connecting said approach control relay in circuit with one track rail of one of said sections and one track rail of the other of said sections.

5. In combination, two railway tracks over which traffic moves in but one direction, an insulated track section for each of the two tracks of said railway, means for supplying coded trackway energy to the track rails at the exit end of each of said sections, a code responsive track relay connected to the rails at the entrance end of each of said sections, an approach control relay, and means controlled by each of said track relays for connecting said approach control relay in circuit with-one track rail of one of said track sections and with one track rail of the other of said sections whereby control of said approach control relay is established by traflic conditions in each of said sections Without employing line wires.

6. In combination, two railway tracks over which trafiic moves in but one direction, an insulated track section for each of the two tracks of said railway, means for supplying coded trackway energy to the track rails at the exit end of each of said sections, a code responsive track relay connected to the rails at the entrance end of each of said sections, an approach control relay, and a phantom circuit for said approach control relay controlled by each of said track relays and including in parallel the track rails of one of said track sections and also including in parallel the track rails of the other of said track sections.

'7. In combination, a multiple track railway provided withtwo tracks over which traffic moves in but a single direction, an insulated track section for each of the two tracks of said railway, means for supplying trackway energy to the rails at the exit end of each of said sections, a track relay connected to the rails at the entrance end of each of said sections, a normally dark signal for each of said tracks for controlling traffic in advance of said sections, an approach control relay for at times operating both of said signals to the illuminated condition, and a circuit for said approach control relay controlled by each of said track relays and including at least one track rail of each of said sections.

8. In combination, a double track railway, an insulated track section for each of the two tracks of said railway, means for supplying trackway energy to the rails at the exit end of each of said sections, a track relay connected to the rails at the entrance end of each of said sections, a normally dark signal for each of said tracks for controlling traffic in advance of said sections, approach control relay means for at times operating both of said signals to the illuminated condition, a non-train-shuntable circuit for said approach control relay means including both track rails of each of said sections, and means controlled by each of said track relays and interposed in said circuit of said approach control relay means whereby said relay means is caused to operate both of said signals to the illuminated condition whenever either or both of said sections is occupied.

9. In combination, a section of railway track over which trafiic moves in a given direction and having means for supplying trackway energy to the rails at the exit end of the section, a track relay connected to the rails at the entrance end of said section, an auxiliary conductor, a device located in advance of said section, an approach control relay located adjacent such device, means controlled by said approach control relay for governing the operation of said device, and circuit means controlled by said track relay for connecting said approach control relay in circuit with said auxiliary conductor and with both track rails of said section in parallel.

10. In combination, a section of railway track over which trafiic normally moves in but a given direction and having means for supplying periodically interrupted trackway energy to the rails at the exit end of said section, a track relay connected to the rails at the entrance end of said section and arranged to follow the periodic interruptions of the trackway energy, a control device located in advance of said section, an auxiliary conductor extending from the entrance end of said section to a point adjacent the position of said device, an approach control relay, circuit means including said auxiliary conductor and at least one track rail of said section for energizing said approach control relay, a source of current connected over a front contact of said track relay to said circuit means, and means controlled by said approach control relay for governing said control device.

11. In combination, a section of railway track over which trafiic normally moves in but a given direction and having means for supplying periodically interrupted trackway energy to the rails at the exit end of said section, a track relay re-,

sponsive to the periodically interrupted trackway energy and connected to the rails at the entrance end ofsaid section, a control device located in advance of said section, an auxiliary conductor extending from the entrance end of said section to a point adjacent the position of said device, a code following track repeater relay, a circuit including said auxiliary conductor and at least one of the track rails of said section for said track repeater relay, means controlled by said track relay for supplying periodically interrupted or coded energy to said circuit, an approach'control relay, means for energizing said approach control relay whenever coded energy is supplied to said track repeater relay, and means controlled by said approach control relay for controlling said control device.

JOHN H. BROADBENT. 

